The advantage of adding the pretest in the nonequivalent control group design is that it
a. guarantees that the maturation threat to internal validity will not be a problem.
b. lets the researcher know if the selection threat to internal validity has resulted in groups that differ at the start of the study.
c. lets a researcher adjust the sample if there is a high level of attrition among participants.
d. increases the validity of the design by allowing for counterbalancing of groups.
Question 2
The threat to internal validity called statistical regression involves the fact that
a. people's scores on repeated tests are not likely to be identical on each testing.
b. changes in the nature of the testing situation lead to different scores.
c. scores in time series designs tend to rise over time.
d. the random error that produces low or high scores in initial testing is not likely to recur on later testing.